HOB...this is from the INFC Rulebook...hope this helps. By marginal points, I believe they the margin of victory.

Article 2: Marginal Points
Marginal Points shall be calculated for each divisional game played throughout the regular season. Post-Season eligibility and seeding shall be de- termined utilizing marginal points. The maximum number of marginal points per game shall be eight points. No team shall add or subtract more than eight points per game.
A. The maximum number of marginal points for any games that went into overtime shall be plus or minus one point.
B. If two teams are tied (on marginal points), the advancer shall be the team that defeated the other during the regular season.
1. If three teams are tied (on marginal points), the advancer shall be determined by coin toss at a time and place determined by the Commissioner.
2. Remaining playoff spots for tied teams, which lose the coin toss, shall be determined by which team defeated the other during the regular season play.